Overrides

Overrides are specific permissions designed to override a
role in a specific context, allowing you to "tweak" your
permissions as required.

For example, if users with the role Student in your course
can usually start new discussions in forums, but there is
one particular forum for which you want to restrict that
capability, then you can set an override that PREVENTS
the capability for Students to "Start new discussions".

Overrides can also be used to "open up" areas of your
site and courses to give users extra permissions where
it makes sense. For example, you may want to experiment
giving Students the ability to grade some assignments.

The interface is similar to the one for defining roles,
except sometimes only relevant capabilities are shown,
and you will also see some capabilities highlighted to
show you what the permission for that role would be
WITHOUT any override active (ie when your override is
set to INHERIT).